In the early days of New Girl, Jess Day (Zooey Deschanel) was a toddler-sized tutu made flesh: cute, affected, hard to actually dislike, but earning grins largely by doggedly evoking childhood's clumsy and doomed attempts at grace. Building a comedy around her resulted in a one-note dynamic in which her three male roommates were forever goggle-eyed at the things she didn't know, couldn't do, or couldn't bear to think about, only to find themselves ultimately unable to really relate to her but also unable to resist her, the way you might be unable to resist a sudden infestation of baby koalas.
But as the show matured through its first season, it emerged as much more of an ensemble, with the flavor of Jess' social idiosyncrasies adjusted from scorched-sugar bitterness to something more complex, while those of Schmidt (Max Greenfield) and Nick (Jake Johnson) emerged more sharply. (Candidly, the show has yet to find a bead on Lamorne Morris' Winston, who changes from week to week while Schmidt and Nick become just as indelible and oddballsy as Jess.)
The writing got sharper, everybody stopped putting all their creative weight on Deschanel's ability to open her eyes even wider than last week, and it began to feel like a real show. It wasn't just that they got better at making Nick and Schmidt funny — though they did — it was that they got better at making Nick and Schmidt weird, and lost, and charmingly devoid of grace, just like Jess, so that she didn't have to be that way, all the time, to the utmost degree, about everything.
These days, Jess isn't as confused and isn't as excited; she's legitimately got her own vibe. The writers figured out that marching to the beat of one's own drummer is supposed to feel like a choice; if you're doing it because you're too dumb to walk and listen to drums at the same time, that's not the same thing.
Then, about three-quarters of the way through their second season, they decided to do one of the toughest things in the world to get right: they head-on addressed whether something was maybe going to flare up between Jess and Nick, who had done both a lot of platonic bonding and a lot of slightly less platonic bonding as time went on. Now, the legitimate dangers of getting characters together are overblown as a general matter and the Moonlighting curse is a fiction (at least as applied to Moonlighting). But with these two, who had begun at the opposite ends of the spectrum of normalcy and function, where Nick was the level-headed roommate and Jess often came off like an alien from a polka-dotted planet, the trick was to make it seem like he wasn't a grown man hooking up with an intellectual 12-year-old because she was pretty and simple. She could not continue as a person who couldn't stand up in high-heeled shoes or successfully step onto an escalator; to have an adult relationship, even in a comedy, she had to be written as an adult.
In that sense, while the fear is always that delving straight into your will-they-or-won't-they dynamic is detrimental to the chemistry of your show, it was hugely helpful to this one. Persuasive romances require some level of parity between personalities, and sexy ones require everyone to seem like they've completed adolescence. It was very canny to make the first Nick/Jess smooch, in the episode "Cooler," surprisingly hot rather than warmly awkward, which it easily could have been. For them to kiss like nervous teenagers would have been kind of expected; for them to kiss like that actually added something.
The writers have continued to make unexpected choices and provide incremental progress, mixing episodes in the Nick-Jess story that seemed chemistry-driven with ones that seemed friendship-driven, so that it was presented as the thing that would create the most challenging problem for true friends: a blistering desire to make out grounded by a bond that's important enough that nobody wants to mess it up. That's meant that the romance outwardly happens in fits and starts and impulsive decisions, but also, underneath, moves along an unnerving but steady emotional track.
It's been pretty terrific storytelling, and pretty romantic and sexy, and for a show that started out seeming like Dumb Snow White And The Three Patient Older Brothers, it's quite an accomplishment.